How to enable Exchange 2010 prelicensing?

Hi,

Just got a quick question: how does one enable Exchange 2010 pre-licensing?

The paragraph below talks about enabling IRM features...but which one? Is it: InternalLicensingEnabled?

From MS:

"To view IRM-protected messages and attachments, Exchange 2010 automatically attaches a prelicense to protected messages. This prevents the client from having to make repeated trips to the AD RMS server to retrieve a use license, and enables offline viewing of IRM-protected messages and attachments. Prelicensing also allows IRM-protected messages to be viewed in Outlook Web App.When you enable IRM features, prelicensing is enabled by default. "

Thanks.

SK